The present disclosure relates to an image reading device and an image forming apparatus including the image reading device.
In general, in an image reading device, a contact image sensor (CIS) is known to be used as an image sensor for reading an image of a document. In addition, a CIS module having a plurality of channels may be adopted for improving a speed at which an image is read.
The CIS module having the plurality of channels emits light to a main-scanning area along one straight line. Furthermore, the CIS module having the plurality of channels is able to output detection data of an amount of received light from each of a plurality of partial scanning areas each forming a part of the main-scanning area, at an individual channel for each partial scanning area. The detection data is data representing the amount of the received light and also image data representing the density of an image in the main-scanning area.
At the time of maintenance of the image reading device, etc., the CIS module having the plurality of channels may be replaced with a compatible module different in type from the module used so far. In this case, the conditions of an image reading process may need to be changed in accordance with the type of the CIS module after the replacement.
Conventionally, it is known that the type of the CIS module is determined in accordance with the durability of a period when an image signal outputted from the CIS module having the plurality of channels is acquired. Accordingly, the conditions of the image reading process can be changed in accordance with the determined type of the CIS module.